M&S says

This feminine bra is a beautiful floral jacquard detail with lace to create a truly stunning piece. The full cups are non-padded and use wiring to work with your natural shape to create a flattering curve that offers maximum support. Added stretch and adjustable straps help create the best fit for you, while a centre bow detail finishes this intricate bra off. For a gorgeous design that is as practical as it is pretty, this non-padded bra is the perfect option.